Michelson interferometers use optical path differences between optical paths L1 and L2 in the figure.

With the same lengths of L1 and L2 and an optical path difference, a circular interference fringe moves to indicate optical path differences of 1/4 wavelength.

Optical path diagram

Key features

Has a wide range of applications, including measurement of microscopic length, light wavelength, and wavelength ratio, refractive index, dispersion, surface roughness, and thin films.

	Points
The Michelson interferometer splits an optical path. Make sure no other factors such as convective airflow are present that would generate optical path differences.

Key features of Sigma Koki products

In applications that use femtosecond lasers, the pulse width of the laser can be expanded by dispersion caused by mirror medium, since the bandwidth of the laser is broader. Precise dispersion control is essential for stability and accuracy of the products.

Based on a dispersion measurement device that incorporates a Michelson interferometer and Sigma Koki's proprietary vacuum deposition technology, negative-dispersion mirrors (GFM series) ideally suited for compression of femtosecond pulses are now commercially available.

Application (light element dispersion measurement device)